Method and apparatus for heating a liquid storage tank

ABSTRACT

A method and apparatus for heating a liquid storage tank includes a liquid storage tank having an interior and a peripheral sidewall. An engine compartment is appended to the peripheral sidewall in front of the heat tube. An engine is disposed in the engine compartment. Heat given off from the engine during operation heats the engine compartment and such heat is transferred through peripheral sidewall to the interior of the liquid storage tank. An exhaust conduit extends into the interior of the liquid storage tank. Heat from hot exhaust gases passing through the exhaust conduit heats the interior of the liquid storage tank.

FIELD

The present invention relates to a method and an apparatus for heating a liquid storage tank.

BACKGROUND

Most producing oil wells within the Province of Alberta and Saskatchewan are set up in a similar fashion. A drive head is positioned on a well head. A production flow line extends from the well head to a liquid storage tank, which is spaced a distance from the well head. A propane burner shoots flame into a fire tube in the liquid storage tank. An engine positioned in a wooden shack adjacent to the well head, provides motive force to the drive head. Propane tanks positioned adjacent to the liquid storage tank, provide a fuel source for the propane burner and the engine respectively.

SUMMARY

According to one aspect of the present invention there is provided an apparatus for heating a liquid storage tank which includes a liquid storage tank having an interior and a peripheral sidewall. An engine compartment is appended to the peripheral sidewall. An engine is disposed in the engine compartment. Heat given off from the engine during operation heats the engine compartment and such heat is transferred through the peripheral sidewall to the interior of the liquid storage tank. An exhaust conduit extends into the interior of the liquid storage tank. Heat from hot exhaust gases passing through the exhaust conduit is transferred to the interior of the liquid storage tank.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features of the invention will become more apparent from the following description in which reference is made to the appended drawings, the drawings are for the purpose of illustration only and are not intended to in any way limit the scope of the invention to the particular embodiment or embodiments shown, wherein:

FIG. 1 is a side elevation view of a well site utilizing an apparatus for heating a liquid storage tank constructed in accordance with the teachings of the present invention.

FIG. 2 is a top plan view of the well site utilizing the apparatus illustrated in FIG. 1.

FIG. 3 is a top plan view of the liquid storage tank illustrated in FIG. 1.

FIG. 4 is a front elevation view of the liquid storage tank illustrated in FIG. 1.

FIG. 5, labelled as PRIOR ART, is a top plan view of a prior art well site.

FIG. 6 is a side elevation view of the well site utilizing a variation of the apparatus illustrated in FIG. 1.

FIG. 7 is a top plan view of the well site using the variation illustrated in FIG. 6.

FIG. 8 is a front elevation view of the variation illustrated in FIG. 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

The preferred embodiment, an apparatus for heating a liquid storage tank generally identified by reference numeral 10, will now be described with reference to FIG. 1 through 8.

Referring to FIG. 5, there is illustrated a prior art well site, generally indicated by reference numeral 100. Well site 100 includes a liquid storage tank 12 having an interior 14, a peripheral sidewall 16 and a heat tube 17. A primary propane tank 20 provides fuel to a burner 21. A secondary propane tank 23 provides fuel to an engine 24 that is housed separate and apart from liquid storage tank 12. The engine 24 has exhaust conduits 36 that expel the exhaust from the engine directly to the outside. Hydraulic flow lines 26 driven by hydraulic pump 48 extend from engine 24 to drive head 28. A production line 30 extends from a well head 32 to liquid storage tank 12.

Structure and Relationship of Parts:

Referring to FIG. 1, apparatus 10 includes a liquid storage tank 12 having an interior 14, a peripheral sidewall 16 and an engine compartment 18 appended to liquid storage tank 12. Referring to FIG. 6, engine compartment 18 may be closed by a door 19 to improve heat transfer to tank 12. Referring to FIG. 2, primary propane tank 20 provides fuel through fuel line 22 to engine compartment 18. Referring to FIG. 1 and 3, an engine 24 is disposed within engine compartment 18. Referring to FIG. 8, the flow of propane to engine 24 is controlled by a gas tree 25 and gas scrubber 27. Referring to FIG. 2, hydraulic flow lines 26 extend from hydraulic tank 29 in engine compartment 18 to drive head 28. Hydraulic fluid may be cooled by a fan 49 as shown in FIG. 7. Referring to FIG. 2, a production line 30 extends from well head 32 to liquid storage tank 12. Hydraulic flow lines 26 are in a substantially parallel orientation and in close proximity to production line 30. Referring to FIG. 3, engine 24 has exhaust manifold 34 which is connected to an exhaust conduit 36 which extends from peripheral sidewall 16 into interior 14 of storage tank 12. In the illustrated embodiment, exhaust conduit 36 is in the form of a substantially horizontal loop that, upon exiting peripheral sidewall 16, is adapted with a muffler 38. Exhaust conduit 36 is further adapted with interior baffles 40. Referring to FIG. 6, in another embodiment, a thermostatically controlled valve 44 is positioned along engine exhaust conduit 36. Thermostatically controlled valve 44 is also connected to an exhaust bypass conduit 37 such that, when activated, the exhaust is redirected through exhaust bypass conduit 37. An engine coolant conduit 42 extends below exhaust conduit 36. In FIG. 3, engine coolant conduit 42 is positioned concentrically within exhaust conduit 36. However, it is preferred that engine coolant conduit 42 and exhaust conduit 36 be separated, as shown in FIG. 6. Referring to FIG. 6, engine coolant conduit 42 is connected to a coolant reservoir 43 and engine 24.

Coolant conduit 42 is positioned below the exhaust conduit 36 and proceeds horizontally below the exhaust conduit 36 before returning to engine 24. It will be appreciated that other configurations of routing may be made. Referring to FIG. 3, engine coolant conduit 42 extends to a booster pump 46 that also returns engine coolant to engine 24 to assist the water pump in engine 24, which may not have enough power to circulate the coolant by itself. Engine 24 is further adapted with hydraulic pump 48 that provides hydraulic pressure to hydraulic flow lines 26.

Referring to FIG. 6, in some circumstances, the fluids held in liquid storage tank 12 contain suspended solids, or solids are transported with the fluids as they are deposited in liquid storage tank 12, such as sand. As the liquids are stored, the solids settle out and come to rest on the bottom of tank 12. When this is the case, it has been found that the fluids stored in storage tank 12 can be more effectively heated by raising engine compartment 18 relative to the bottom of liquid storage tank 12, such that at least a portion of the engine compartment is inset within the periphery of the storage tank 12 at a higher position than would otherwise be the case. As it is raised, it may be necessary to include a floor 54 with rails 56, a support 58, and stairs 60 shown in FIG. 7. Referring to FIG. 8, compartment 18 may also have a vent 62, and an engine guard 64 to prevent individuals from entering the compartment during operation.

Operation:

The operation of apparatus 10 in accordance with the teachings of a preferred method will now be described with reference to FIG. 1 through 8.

Referring to FIG. 3, engine 24 is operated within engine compartment 18. Referring to FIG. 2, fuel for the operation of engine 24 is provided by primary propane tank 20 through gas tree 25. No other source of fuel is needed. The noise of engine 24 is dampened by muffler 38 and absorption of sound by liquid storage tank 12 through peripheral sidewall 16. Heat 50, given off from engine 24 during operation, heats engine compartment 18 and such heat is transferred through peripheral sidewall 16 to interior 14 of liquid storage tank 12. Hot exhaust gases 52 from engine 24 pass through exhaust conduit 36 and heat 50 given off heats interior 14 of liquid storage tank 12. Interior baffles 40 disrupt the linear flow of hot exhaust gases 52 to more evenly distribute and transfer heat from hot exhaust gases 52 through exhaust conduit 36 to interior 14 of liquid storage tank 12. Referring to FIG. 6, engine coolant conduit 42 is disposed below the exhaust conduit 36. Heated engine coolant passes through engine coolant conduit 42 such that heat 50 is added to further transmit heat 50 to interior 14 of liquid storage tank 12. For operation in warmer conditions, thermostatically controlled valve 44 diverts heated engine exhaust to the bypass conduit 37. This allows 50% of the engine heat out of the 14 tank interior, the heated engine coolant is cooled and, in turn, moderates the temperature of interior 14 of liquid storage tank 12. Referring to FIG. 1 and 2, apparatus 10, by configuring hydraulic lines 26 in a substantially parallel orientation and in close proximity to production line 30, production fluid within production line 30 is also heated.

In this patent document, the word “comprising” is used in its non-limiting sense to mean that items following the word are included, but items not specifically mentioned are not excluded. A reference to an element by the indefinite article “a” does not exclude the possibility that more than one of the element is present, unless the context clearly requires that there be one and only one of the elements.

It will be apparent to one skilled in the art that modifications may be made to the illustrated embodiment without departing from the spirit and scope of the invention as hereinafter defined in the Claims. 

1. An apparatus for heating an oil well production storage tank, comprising: an oil well production storage tank having an interior, a peripheral sidewall, a bottom, and an engine compartment that houses an engine appended to the peripheral sidewall to effectively share a portion of the peripheral sidewall with the tank, wherein at least a portion of the engine compartment is inset within a periphery of the tank, the engine compartment being elevated above the bottom of the tank such that any settled solids in the tank are below the engine compartment; an engine disposed in the engine compartment, such that heat given off from the engine during operation heats the engine compartment and such heat is transferred to the interior of the tank through the portion of the peripheral sidewall that is shared by the engine compartment and the tank; and an exhaust conduit extending into the interior of the tank, such that heat from hot exhaust gases passing through the exhaust conduit is transferred to the interior of the tank.
 2. The apparatus as defined in claim 1, wherein the engine is selected based upon the heat the engine generates during operation.
 3. The apparatus as defined in claim 2, wherein the engine is a marine engine or a conventional engine.
 4. The apparatus as defined in claim 1, wherein the exhaust conduit extends horizontally to exterior of the engine compartment.
 5. The apparatus as defined in claim 1, wherein the engine is used to operate a drive head on a well head of an oil well.
 6. The apparatus as defined in claim 5, wherein hydraulic flow lines from the engine to the drive head extend along a production flow line extending from the well head to the tank.
 7. The apparatus as defined in claim 1, wherein an engine coolant conduit extends from the engine into the interior of the tank, such that heat from heated engine coolant adds heat to the interior of the tank.
 8. The apparatus as defined in claim 7, wherein the engine coolant conduit passes along one of an interior or an exterior of the exhaust conduit and loops back to the engine.
 9. The apparatus as defined in claim 1, wherein the exhaust conduit has interior baffles.
 10. An apparatus for heating an oil well production storage tank, comprising: a liquid storage tank having an interior, a peripheral sidewall, a bottom and an engine compartment housing an engine that effectively shares a portion of the peripheral sidewall with the tank, wherein at least a portion of the engine compartment is inset within a periphery of the liquid storage tank, the engine compartment being elevated above the bottom of the tank such that any settled solids in the tank are below the engine compartment; and an engine disposed in the engine compartment, such that heat given off from the engine during operation heats the production storage tank and such heat is transferred by radiation from the engine compartment to the interior of the liquid storage tank through the portion of the peripheral sidewall that is shared by the engine compartment and by at least one of exhaust gas conduit, coolant conduit and hydraulic fluid conduit. 